1. Field Of The Invention
This invention relates to a method for protecting submerged wooden structures, such as wood pilings, from attack by marine organisms, such as marine borers. The invention prolongs the life and serviceability of submerged pilings and the like.
2. Description Of Related Art
Wooden piling has been used for many years to support piers, wharves, and for slips and the like. It is well-known that such piling is subject to many hazards necessitating replacement of the piling. One major source of damage is plant and particularly marine life. Certain parasites and microorganisms are particularly troublesome for wooden structures. Marine organisms known as limnoria, gribbles and teredo or shipworms are prevalent in shore waters and commonly infest submerged wooded structures seriously sapping the strength and life of the structures.
Previous efforts to safeguard against these hazards include the impregnation of the structures and/or the coating of their surfaces with special preservatives and protective coatings using materials such as creosote, tar, impervious paint and many others. While these materials do protect against certain hazards, they are quite ineffective with respect to others. More importantly, these chemical treatments are subject to leaching, scaling and erosion by the action of the constantly moving, surrounding water, temperature changes, shock forces and oft repeated application and relief of load forces. The high salinity and other constituents of sea water also contribute to degradation of these protective measures.
Various guard devices also have been proposed for installation about pilings. One prior art protective measure involved enclosing portion of the piling in direct contact with the water with a plastic sheet by wrapping the sheet tightly around the pile. Piling also has been encased with rigid polyvinyl chloride tubing. This method provides a barrier to access by marine life not already present in or on the piling and traps that life present in and on the piling inside the jacket. Rapid depletion of any oxygen present between the protective wrapping and the wood piling deprives marine life of this vital gas and arrests further damage to the piling. While this measure can prove quite effective, prior art techniques for implementing it have proved to be rather cumbersome. Moreover, the jacketing which is intended to wrap tightly around the piling often has a loose set with the result that wave action and other water currents along the shore line causes undesirable wear and often premature failure. Representative of this basic prior art approach are Liddell U.S. Pat. Nos. 3,027,610; 3,103,103; 3,321,924 and 3,372,552; Plummer U.S. Pat. No. 3,181,300 and Maurer U.S. Pat. No. 3,999,399.